Process for producing pantothenic acid



- Patented Apr. 15, 1947 I Dilworth T. Rogers, Pearl River, N. Y., assignor,

by mesne assignments, to American Cyanamid Company, New York, N. Y., a corporation of Maine No Drawing. Application March 19, 1941, a

- Serial No. 384,226

This invention relates. to the preparation of biologically active substances and more particularly relates to a method for the preparation of pantothenic acid. a

In accordance with the present invention I have found that pantothenic acid can be prepared by fusing a-hydroxy-fifi-dimethyl-y-butyrolactone with p-alanine. In carrying out the fusion reaction the ratio of the reactants can be varied wlthin'certain reasonable limits and the conditlons under which the fusion is carried out may also be varied over a considerable range. I usually prefer to use approximately equivalent molecular proportions of the fi-alanine and the u-hydroxy-p,p-dimethyl-y-butyrolactone. However, a desirable product can be obtained using either an excess of B-alanine or an excess of the a-hydroxy-p,p-dimethyl-y-butyrolactone. I prefer to carry the fusion out at a temperature of about 150 C. and employing this temperature, the reaction ls usually complete in about-two hours, and there is no appreciable decomposition. The reaction can be carried out at a temperature of about 100 0.; however, at this temperatur an exce'ssivelylong period of heating is required. When the fusion is carried out at a temperature of about 200 C. a solution'is obtained and the reaction appears to be complete in from five to 5 Claims. (01. 260-534) 2 it is believed that the improved yields may be due to the increased miscibility of the reactants in the presence of the moisture.

particular examples, however, are given for purtenminutes; however, at this high temperature 7 the reaction may be accompanied by some decomposition. Usually the fusion is carried out'employing analytically pure fl-alanine and analytically pure e-hydroxy-p,fl-dimethyl-Y-butyrolactone since the final product is used primarily for biological purposes. It is to be understood, however, that relatively impure reactants may be employed and still produce pantothenic acid which can easily be purified by known methods to produce a pure product. In the processes for producing p-alanine frequently the final product 7 contains some impurities in the form of sodium fi-alenate or ammonium p-alanate depending upon the process used in making the p-alanine."

The presence of this small quantity of sodium or ammonium fi-alanate does not interfere with the fusion reaction and in fact may actually serve to increase the yields of pantothenic acid when f fused with a-hydroxy- 8,19-dimethyl--y -butyrolectone.- In some instances it may be desirable to add a diluent to the reaction mixture. For example, when a small amount of water is added 7 to the reaction mixture there appears to bea slight increase in yield. The amount of water added is, of course, a relatively small amount,

The following examples represent suitable methods for carrying out the reaction. These poses of illustration only and the invention is not to be strictly limited to the details set forth therein.

' Example 1 1.46 g. of a-hydroxy-'e,p-dimethyl-y-butyrolactone was fused with one gram of B-alanine at C. for about two hours. Biological assays of the fusion product on Lacto basillus casei E indicated that about 12.8% coupling had taken place.

' Example 3 j A fusion similar to that described in Example 1 was carried out using 4.5 g. of a-hYdIOXY-BJS- dimethyl-y-butyrolactone and 3.0 g. of an impure fi-alanine containing about 3.22% ash. In

this example two'drops of water-was added to I the mixture and the fusion was carried out at rs temperature of about C. and fora period of one hour. A biological assay in this case indicated that 17.6% coupling had taken place.

Example 4 only slightly less than the reactions carried out at 150 0. However the reactions were generally and it is not suflicient to act as a; solvent, and 56 "accompanied by some decomposition and the pantothenic acid produced was difllcult topuriiy.

' cal activity.

. butyrolactone can be produced by known methods 01' resolution from the dl-a-hydroXyfl.fi-di- The raceinic dl-iorm or the u-hydroxy-dp-cflv methyl-y-butyrolact'one was used in the above examples. The pantothenic acid produced, there forc, is a. mixture of the d and l pantothenlc acids. Only the d-form of the pantothenicacid has biological activity. Therefore, the products obtained by the above fusions possess only about half as much activity as does d-pantothenic acid.

-By using levo-a-hydroxy-p,p-dimethyl-'y-butyrolactone instead 0! the racemio lactone in the above examples. the resulting pantothenie acid produced is the d-i'orm and possesses full biologi- Levo-a-hydroxy-fi.fl-din ethy1--ydroxy-B,s-dimethy1-- .-butyrolactone.

2.,1he process of producing pantothenic acid which comprises iusin: p-alanine with a-hy- 4 droxy dp-dimethyl-'y-butyrolactone at a temperature oi about 150 C.

3. The process of producing pantothenic acid which comprises fusing p-alanine with a-hydro Y-Bfi-dlmethyl-v-butyrolactone at a temperature of about 150 C. and for a period of about two hours.

4. A process of producing pantothenic acid which comprises fusing 'a mixture of fi-alanine and -hydroxy-p,p-dimethyl-'y-butyrolactone to which has been added a small amount of water.

5. A process of producing d-pantothenic acid which comprises fusing p-alanine with levo-ahydroxy-pp-dimethyl-y-butyroiactone at a. temperature of about 150C.

nmwoa'm '1'. Rooms.

REFERENCES CITED The following references are of record in the file oi this patent:

UNI'I'ED sums 'PA'rEN'rs Name I Date Moore July 22, 1940 OTHER REFERENCES Number Williams et 9.1., J. Am. Chem. Soc.,"'vol. 62,. pp. 1784-85. (Copy in latent Ofl. Lib.) 

